Getting charged a penalty fee and interest for something COJ did not do!

It has been almost three months and the old COJ bill has not been closed yet and the funds have not been transferred into the new account. I have already logged two queries yet nothing has been done. The COJ has not only charged me interest for the outstanding amount they were meant to transfer from the old bill but also charge me a final penalty fee for something they did not do. This is extremely frustrating. The old account belonged jointly to my ex and I where I paid for it since October last year and the new account is a transfer to my own name.